Radio tuning device



- March 18, 1941. w. H. MURRAY RADIO TUNING DEVICE 4 sheets-sheet 1Filed May 22, 1939 3mm WHMarrag I N 'gil SSN UT @www March 18, 1941. w.H MURRAY 2,235,722

RADIO TUNING DEVICE Filed May 22, 1939 4 Sheets-Sheet 2 l 4530/54 4530155 4530 /z-i-S 79 WI' il om 4W 94M NORM/.54,

i 47 WHMW@ March 18, 1941. w, H, MURRAY 2,235,722

RADIO TUNING DEVICE Filed May 22, 1939 4 Sheets-Sheet 5 gz WHMur-ray 4'5 @a s( @www March 18, 1941. w. H. MURRAY RADIO TUNING DEVICE PatentedMar. 18, 1941 UNITED STATES PATENT OFFICE Claims.

This invention relates to radio tuning devices and more particularly toan automatic time controlled device for use in combination with a radioreceiver having automatic station selecting means 5 associatedtherewith.

An object of this invention is to provide a time controlled means incombination with a push button tuning device incorporated in a radio forautomatically tuning the radio receiver to a selected station at apredetermined time.

Another object of this invention is to provide an electrically operatedradio tuning actuator and means controlling operation of the actuator ata predetermined time.

A further object of this invention is to provide a radio tuning means ofthis kind which is so constructed that one portion of the device may beoperatively connected to the radio set and another portion of the devicemay be disposed remote from the radio set for controlling the operationof the radio set from a remote point and at a particular time in orderthat a particular radio station may be tuned in by the radio receiver ata predetermined time.

A still further object of this invention is to provide a time controlledand electrically operated ,tuning means in combination with anautomatically operated radio tuning control, the device being soconstructed that any desired number of radio stations may be tuned in atintervals selected by the user of the device, the intervals beingco-ordinated with the beginning of the broadcast of the selected radiostations.

A further object of this invention is to provide in a device of thiskind an automatically operable time controlled tuning means including asolenoid operated circuit making and breaking means and also solenoidoperated circuit breaking means associated with the first circuit makingand breaking means so as to prevent oscillation of the first circuitmaking and breaking means.

Another object of this invention is to provide in a device of this kinda controlling switch whereby the device may be readily cut off in orderto permit manual operation of the radio apparatus.

To the foregoing objects and to others which may hereinafter appear, theinvention consists of the novel construction, combination andarrangement of parts as will be more specifically referred to andillustrated in the accompanying drawings, wherein is shown an embodimentof the invention, but it is to be understood that changes, variationsand modifications may be resorted to which fall within the scope of theinvention as claimed.

In the drawings:

(Cl. Z50-20) Figure 1 is a vertical section of a radio tuning deviceconstructed according to an embodiment of this invention mounted on aradio shown in fragmentary side elevation,

Figure 2 is a vertical section of the control 5 means for the operatorshown in Figure 1,

Figure 3 is a sectional View taken on line 3-3 of Figure 2,

Figure 4 is a diagrammatic view of the electric circuits embodied inthis invention, l0

Figure 5 is a fragmentary Vertical section partly in detail taken online 5-5 of Figure 3,

Figure 6 is a vertical section partly in detail taken on line 6-6 ofFigure 3,

Figure 7 is a fragmentary side elevation of the 15 structure shown inFigure 2,

Figure 8 is a fragmentary sectional view on an enlarged scale taken onthe line 8-8 of Figure 3,

Figure 9 is a longitudinal section taken through a modified form of thisinvention, 20

Figure l0 is a fragmentary plan view of the circuit closing meansembodied in the structure shown in Figure 9, and

Figure 11 is a vertical section through the drive means incorporated atone end of the structure 25 shown in Figure 9.

Referring to the drawings, the numeral I5 designates generally a radiocabinet including a push button or lever operated tuning means I6. Thetuning means I6 at present forms a part of 30 the radio apparatus I5 andin the present instance, the tuning means I6 is constructed in the formof a push button although if desired, the tuning member I 6 may be apivoted or slidable tuning means. A housing I'I is mounted in face 35abutting relation to the front of the cabinet I5 and comprises a frontwall I8, a rear wall I9 provided with an opening 20 through which thetuning operator I 6 is adapted to project. A top wall 2I is secured tothe side walls I8 and I9 and the 40 end walls 22 and a bottom wall 23 issecured to the lower ends of the front and rear walls I8 and I9 and theend walls 22.

A plunger `or slide member 24 is slidable in a bearing or cylindricalbushing 25 secured to the 45 fron-t wall I8 and is provided at itsforward end with a head 26 disposed in confronting rela-tion to thebutton or tuning operator I6. A lever or plunger operator 2l is rockablymounted on a shaft 28 carried by the housing I'I and is provided 50 withan elongated slot 29 through which a pin 30 engaging through la slot 3|in the plunger 24 is adapted to engage. The pin 30 engages against oneend of a spring 32 positioned about the plunger 24 and the opposite endof the spring engages 55 against the head 25. A solenoid coil 33 issecured in depending relation to the top wall 2| of the housing |1 and amovable core or armature 34 engages within the coil 33 and is providedat its lower end with a head 35. The core 34 is adapted togravitationally move downwardly to an inoperative position. The lever orarm 21 is provided with an angularly 4disposed arm or extension 36 whichextends downwardly from the shaft 28 and the extension 38 is connectedto the solenoid 34 by a link 31. The link 31 is pivotally connected asat 38 to the lower end of the arm or extension 35 and pivotally mounted`as at 39 in a slot 48 provided in the lower side of the head 35. Inthis manner when the core 34 is drawn upwardly by the solenoid coil 53,the -plunger 34 is moved forwardly and to the left as viewed in Figure 1for engagement with the tuning operator I8.

The operator hereinabove described which is mounted in the housing I1and engageable with the tuning button I8 is adapted to be electricallyconnected to a time controlled tuning device shown in Figures 2 to 8inclusive, the operator being interposed in the electric circuits shownin Figure 4, to be hereinafter described.

The tuning operator l1 shown in Figure 1 is electrically connected witha selective and time controlled tuning device generally designated as 4|which comprises a cylindrical s-tationary housing 42 mounted lon a base43. rIhe housing 4| is provided with a top wall 44 which is secured tothe upper end of the cylindrical member 42. The cylindrical wall 42 isprovided with a plurality of circum-ferentially spaced apart openings 45which are arranged in a plurality of vertically spaced apart ser-ies45a, 45h, 45e, 45d, 45e and 45j, the number of rows of openings 45corresponding to the number of buttons carried by the radio apparatusI5. The wall 42 on the inner side thereof is provided with a circularband 48 for each series of openings 45 and leach band 46 is providedwith openings 41 registering with the openings 45. A pair of yieldableclips Vor clamping members 48 are secured to the inner surface or sideof the band 46 and :a metallic key or pin 49 is adapted to be insertedthrough the openings 45 land 48 and is provided at its inner end with agroove or clip engaging portion 58 which is positioned outwardly from arounded head or contact 5| carried by the inner end of the pin 49. Theouter end of the pin 49 is provided with a button or knob 52 preferably,of insulated material so that the key or pin can be handled withoutshocking the person handling the key.

Each row of openings 45 has a band 45 associated therewith and clips orholding members 48 mounted on the inner side thereof for engagement witha key 49. The holes 45 are `arranged in such a manner that the spacebetween each pair of holes is equivalent to a predetermined time and inthe present instance, this time is fteen minutes, being a period ofItime during which certain radio broadcasting stations are :operating ona particular broadcast. A cylindrical member 53 is disposed interiorlyof the hou-sing 4| and is provided with an upper wall 54, thecylindrical member 53 and the wall 54 being for-med of insulatingmaterial. A vertically disposed shaft 55 is rotatably mounted at itslower end in a bearing 55 carried by the base 43 and a second shaft orextension 51 is coupled to the upper end of the lower shaft 55 by aninsulated coupling member 58. The shaft extension 51 is provided withthreads 59 and nuts 88 .and 8| are threaded onto the threads 59 andengage the top wall l54 of the cylindrical member 53 so as to tightlysecure Ithe cylindrical member 53 to the shaft member 51 for rotationthereby.

A worm gear 82 is secured yto the upper end of the shaft member 51 and aworm 83 operated by a clock mechanism 34 engages the worm gear 62 so asto rotate the cylindrical member 53. The clock mechanism 84 ispreferably an electrically operated clock mechanism mounted in' thehousing 85 carried by the upper wall 44 of the housing 42 and :anopening 86 is provided in the central portion of Ithe wall 44 throughwhich the shaft 51 projects.

A vertically disposed circuit closing bar 81 is secured as by fasteningmembers 88 to the outer side of the cylindrical member or drum 53 and isadapt-ed upon rotation of the drum 53 to contact with a key or pin 49 ina selected :opening 45. An extension 69 is connected `at one end to oneend of lthe wiper or circuit closing bar 61 and the opposite end of theextension 89 is provided with a downturned portion 18 secured las byfastening means 1| to the lower shaft 55. The bearing 58 for the shaft55 is provided with an extension 12 and a terminal 13 is connected torthe extension 12 so that a wire connected to the terminal 12 will closea circuit as will be hereinafter described upon engagement of the wiperor movable contact bar 81 with a selected key 49.

A cylindrical upwardly extending and transparent member 14 having abottom wall 15 is mounted on the upper Wall 54 of the drum 53-54 and thebottom wall 15 is interposed between the upper wall 54 and the upper nut6| so that the cup-shaped member formed by the wall 14 and the bottom 15will rotate with the circuit closing drum 53-54. The periphery of thecylindrical part 14 is provided with graduations and time indicatingmeans and a pilot light 18 mounted in a socket 11 carried by the bracket18 is supported interiorly of the cylindrical member 14. The outer wall42 of the housing 4| is provided with a window 19 through which thegraduations on the drum 14-15 are visible. The graduations on the drum14-15 are co-ordinated with the clock 85 so that when a selected key 49is mounted in a selected opening 45 a circuit will be closed at aselected time. The bracket 18 is secured by a fastening means 88 to thehousing 4| and in the present instance, is secured to the cylindricalwall 42.

An insulated base member 8| is mounted on the base 43 Within the housing4| and a pair of L- shaped brackets 82 are secured as by fastening means83 to the base member 8|. A rock shaft 84 is rockably mounted in theupstanding legs 85 of the L-shaped members 82 and a bar or lever 85 issecured to the rock shaft 84. The base 8| has secured to one sidethereof a spring contact clip 81 and the lever or bar 85 has movablymounted thereon a circuit closing pin 83. The circuit closing pin 88 isslidable through the lever or bar 88 and is provided with a shoulder 89limiting the movement in an upward direction of the pin 8B relative tothe bar 8B. A spring 98 is disposed about the pin 88 above the lever 86and at one end engages against the lever 85 and at the other end engagesagainst a shoulder or collar 9| carried by the pin 88 at its upper endso as to constantly maintain the shoulder 89 in engagement with theunder side of the lever 88.

A solenoid coil 92 is supported by a bracket 93 secured as by fasteningmeans 94 to the base 8| and a movable core 95 having a lower head 96 ismovable interiorly of the coil 92. The head 96 is connected to the rocklever 86 by means of a pivoted link 91 so that vertical movement of thecore 96 will rock the lever 86 so as to thereby move the pin or circuitclosing member 88 relative to the clip 81.

A second clip 98 similar to the clip 81 is secured to the base 8| on theopposite side of the rock shaft and the second circuit closing pin ormember 99 is slidably mounted in the opposite end of the rock lever 86.The pin 99 has a shoulder |00 below the lever 86 so as to limit theupward movement of the pin 99 relative to the lever 86. A spring |0| isdisposed about the pin 99 on the upper side of the lever 86 and theupper end of the spring engages a shoulder 92 carried by the pin 99 atits upper end and the lower end of the spring |0| engages the upper sideof the lever 86. The pin 99 is adapted to be connected to one side of anelectric circuit as will be hereinafter described.

A solenoid coil |03 is mounted on a bracket or supporting member |04secured as by fastening means |05 to the base 8| and a movable core |06is movable relative to the coil |03. The core |06 has a head |01 at itslower end which is connected as by a pivoted link |08 to the rock lever86. Through the use of the two solenoid coils 92 and |03 the rock lever86 is rocked in one direction by the coil 92 and in the other directionby the coil |03,

A liquid switch |09 is mounted in a clip or holder ||0 carried by therock shaft 84 and extends transversely of the rock shaft 84, This liquidswitch |09 is adapted to be interposed in an electric circuit which isopened and closed by rocking of the shaft 84 and the lever 86 under theaction of the movable core members 95 and |06. In this manner movementof the lever 86 in one direc tion will operate to break an electriccircuit through the liquid switch |09 and movement of the rock lever 86in the oposite direction will act to close the electric circuitassociated with the switch |09. The lever 86 is provided on its underside with a depending member |21 and a yieldable lever holding member|28 is secured to the base 8| and is engaged with the depending member|21 so as to yieldably hold the lever 86 in a selected positiondetermined by operation of one of the solenoid coils 92 or |03.

A circuit breaking relay generally designated is mounted on a base ||2secured to the base 43 within the housing 4|. This circuit breakingrelay comprises a pair of stationary contacts ||3 and ||4 as havingterminals ||5 and ||6 respectively. These contacts ||3 and ||4 aredisposed in spaced apart relation and are adapted to be connected toelectric circuits to be hereinafter described. A solenoid coil ||1 issupported by a bracket or supporting member ||8 of substantially U-shapewhich is secured to the base ||2. A movable core ||9 is movable withinthe coil ||1 and the core ||9 has a head |20 at its lower end. A contactbridging member |2| is adapted, when in operative position, to bridgethe two contacts 3 and ||4 and is provided with a central opening |22through which a bar |23 slidably engages. The bar |23 at its lower endis provided with a head |24 and the upper end of the bar |23 is securedas at |25 to the head |20. A spring |26 is disposed about the bar |23and the upper end of the spring |26 engages against the head |20 and thelower end of the spring |26 engages against the bridging member |2|.

A transformer |29 is mounted on the base 43 within the housing 4| andthe primary of the transformer |29 is adapted to be connected to asource of electric current supply. The secondary of the transformer 29is adapted to be connected to the solenoids hereinbefore described.

'I'he transformer |29 has the primary coil thereof connected as byconductors |30 and |3| to a source of electric current supply. The clockmechanism 64 is connected as by conductors |32 and |33 to the conductors|30 and |3| respectively. A pilot light |34 is interposed in theconductors |32 and |33.

The liquid switch |09 has one side thereof connected as by a conductor|35 to the conductor |3| and the other side is connected as by aconductor |36 to one side of the radio apparatus I5. The other side ofthe radio apparatus I5 is connected by a conductor |31 to the conductor|30. The secondary |38 of the transformer |29 has a conductor |39connected to one side thereof and a conductor |40 connected to the otherside thereof. The conductor |39 is connected to one side of each of thesolenoid coils 92, |03, and ||1 as shown in Figure 4. The conductor |40is connectedto the terminal 13 which is electrically connected to thewiper or circuit closing bar 6T. A conductor |4| is connected to theupper ring 46 carried by the drum 53 and is also connected to theterminal H5. The opposite side of the circuit breaking relay isconnected as by a conductor |42 to the conductor |4|. The contact ||4 isconnected to the yieldable contact or clip 81 by a conductor |43 andthis conductor |43 is also connected to the yieldable clip or contact98. One side of the solenoid coil 33 of the button operating member isconnected as by a conductor |44 to a ring 46a and the other side of thesolenoid coil 33 is connected as by a conductor |45 to the conductors|39 on one side of the secondary coil |38.

A switch member |46 is secured to the housing 4| and includes a pair ofstationary terminals |41 and |48, the terminal |41 being connected as bya conductor |49 to the conductor |36. The terminal |48 is connected tothe conductor |3|. The switch |46` also includes a second pair ofterminals |50 and I5! and a V-shaped circuit closing blade |52. Theterminal |50 is connected to the conductor |3| so that when the switch|46 is in one position, the position shown in full lines in Figure 4,the long side of the blade |52 will bridge the two terminals |48 and |50to the primary |53 of the transformer |29. In the oppo- Asite position,the long blade of the switch |46 bridges the space between the twoterminals |41 and |5| and the opposite or short blade |54 Will engagethe terminal |50 so that a circuit will be completed from the conductor3| through the conductor |49 and the terminals |41 and |50 to one sideof the liquid switch |09.

In Figures 9, 10 and 11, there is disclosed a slightly modied form ofcontrolling means for the operator disclosed in Figure l. A housing |56is provided including upstanding end walls |51, side walls |58, a bottomwall or base and a rear wall |59. An arcuate or arched front wall |60 issecured to the base wall |58 and the end walls |51 and is provided witha plurality of spaced apart openings |6|. The openings |6| are spacedapart in a manner similar to the openings 45 of the housing 42 and thefront wall |66 is provided with a row of'openings |6| for each tuningmember 5, in addition to a separate row of openings |6| for the maincircuit comprising the conductors |39 and |40 which control the movementof the liquid switch |09. The

abl

front wall is provided on the under side thereof with an elongated stripor band |62 for each row of holes |6I and yieldable clips |63 similar tothe clips 48 are secured to each band |62 so as to yieldably hold acircuit closing key or pin |64 in a selected opening I6I. A flexiblecircuit closing band is disposed in the housing |56 and is trained overa pair of sprockets |66 mounted on a shaft |61 journalled in the housing|56 and is also trained over sprockets |60 mounted on a shaft |69 at theopposite end of the housing |56. The shaft |69 has a worm gear |10secured thereto with which a worm |1| meshes. The worm |1| is carried bya shaft |12 which is operated from a clock or motor mechanism |13 ofconventional construction. The band |65 is preferably formed of metal orconductive material and is provided with a pair of key engaging stripsor bars |14 and |15 which are spaced apart substantially one-half thelength of the band |65. The sprockets |68 are preferably insulated fromthe shaft |69 whereas the sprockets |66 and the shaft |61 are ofconductive material and a terminal |16 is carried by an end wall |51 andis electrically connected to the shaft |61 and the sprockets |66 so asto energize the band |65.

The band |65 is maintained in the desired spaced relation to theunderside of the metal strips |62 by means of an arcuate or arched guidemember |11 which is secured as by supporting brackets |18 to the sidewalls |58 of the housing |56. The housing |56 is provided on theinterior thereof with a relay |18a which is similar to the relayembodied in Figure 2 comprising the solwenoids 92 and |03 and theoperating parts associated therewith. A circuit breaking relay or switchmember |19 is also mounted in the housing |56 and is similar to thecircuit breaking relay I I and a voltage reducing transformer similar tothe transformer |29 is mounted in the housing |56. The electricalconnections between the relays |189, |19 and the transformer |90 aresimilar in every detail to the diagrammatic connections shown in Figure4.

In the use and operation of this radio apparatus tuning means the tuningoperator I1 is adapted to be secured in any suitable manner to the irontface of the radio receiving apparatus I5 so that the tuning members I6will project through the opening 20 into the interior of the housingsupporting the operators. A key member 49 is inserted in a selectedopening 45 and snugly held by means of the clips 48 for wipingengagement with the circuit closing bar 61. The key member 49 shown incontact with the bar 61 will close the lower voltage circuit from thesecondary of the transformer |29 through the conductor |40, conductorI4I, bridg ingmember I2I, conductor |43 and conductor |39. Upon closingof th-e circuit to the secondary |38 of the transformer |29, theelectric current will fiow through the solenoid coil |I1, through theconductor |42 and at this time, the core II9 Awill be raised, moving theswitch operating bar |23 upwardly. In view of the fact that the head |24of the bar |23 is spaced downwardly from the bridging member |2|, therewill be a delay in the breaking of the circuit between the two contactsII4 and H5. This delay in the brea1 ing of the circuit between theconductor I4I and the conductor |43 will permit the electric current toflow to the solenoid |03. When the solenoid |03 is energized the core|06 will be drawn upwardly so as to disconnect the blade or pin 99 fromthe terminal or clip 98. The sliding connection between vthe pin 99 andthe bar 86 will also permit a slight -delay in the breaking of theelectric circuit to the solenoid |03, the bar 86 moving upwardly withthe movement of the core |06 and compressing the spring IOI.

The circuit breaking member II I is provided so as to prevent continuedrocking of the lever 86 and alternate opening and closing of the switch|99 which would result by closing of the electric circuit to the coil|93 which raises one end of the lever 36 until the lever 66 breaks thecircuit to the coil |03. At this time the switch |99 is closed and theopposite end of the lever 86 has closed a circuit through the clip 81and pin 90 to the coil 92. At this time also the circuit breaker I I Ihas broken the circuit from the wire |4| to the wire |43 and thiscircuit will remain broken so long as current ows from wires I4I and |42to th-e coil ||1 and the wire |39, so that even though the coil 92 isconnected through the switch comprising the pin and the clip 91 and coil92 is not energized because the switch comprising the terminals I|4 andII5 and bridging member I2I is open.

Rocking of the bar 86 under the upward movement of the core |96 willcause the liquid switch |99 to be rocked to a circuit closing position,closing the electric circuit from the primary |53 of the transformer |29through the conductors |35 and |36 and the conductor |31 to the radioapparatus. Closing of the liquid switch |99 will effect a closing of themain operating circuit to the radio apparatus I5 so as to energize theradio apparatus.

At the same time that the circuit closing bar 61 engages the key 49, thebar 61 will engage a selected key 49a. which closes a circuit throughthe conductor |44 and the conductor |45 to .the solenoid 33. When thesolenoid 33 is energized, the core 34 will be drawn upwardly andmovement of this core 34 upwardly will effect forward movement of theplunger 24. The head 26 of the plunger 24 will then engage the tuningmember I6 and effect movement `thereof so as to thereby tune a selected.broadcast band in the radio apparatus I5. The forward movement of theplunger 24 is cushioned by the spring 32.

A tuning device constructed according to this invention may be partlyconnected directly to the radio apparatus and another part disposedremote from and connected to the rst part for controlling operation ofthe radio apparatusunder a time controlled means. It will, of course, beunderstood that if desired the time controlled means may be directlyincorporated in the radio cabinet or apparatus, but primarily the deviceis constructed as an attachment for connection to the present structureof radio apparatus provided with selective station tuning devices. Thetime controlled tuning means hereinabove described may be `either cut onor on by operation of the manually operable switch |46 which isconnected to the transformer |29 and also to the liquid switch |09. Ifit is desired to manually control the radio apparatus the switch |46will be positioned as shown in full lines in Figure 4.

However, if it is not desired to control the radio apparatus by thehereinb'efore described time controlling means, the switch |46 is movedto the dotted line position shown in Figure 4 wherein the blade |52bridges the two terminals |41 and I5! and the blade |54 bridges theterminals |59 and I5I.

vThe radio receiving apparatus I may be cut oir at a predetermined timeby inserting a second key 49 in a succeeding opening 45 so that when theclock mechanism 65 rotates the drum 53,4the bar 61 will contact thesecond k-ey 4t and thus close the circuit through the conductors |39,|40, |4| and |43 to the solenoid coils Ill, 92 and |03. While the radioapparatus is in operation the switch |09 is closed and the pin 9D is incontact with the terminal 81. Upon closing of the circuit by thesucceeding pin di, the solenoid coil 92 will be energized so as to movethe pin 9) to a released position, thus moving the bar 86 to a positionwhereby the switch |09 will be in a circuit breaking position. In thismanner the radio apparatus l5 may be cut off at any predetermined timeand if it is desired to turn the radio apparatus on again at asucceeding time, an additional pin or key 49 may be inserted in afurther succeeding opening or socket 45.

What I claim is:

1. An attachment for a radio receiving apparatus having selective tuningmembers, an electro-magnetic operating member for each tuning member,circuit closing means for said operating member, a switch connected tothe supply source for the radio apparatus and connected to the radioapparatus, a switch operating circuit, an electro-magnetic operatorconnected to said switch for moving said switch to a circuit closingposition, a second electro-magnetic operator connected to said switchfor moving said switch to a circuit breaking position, a single electriccircuit for said electro-magnetic operators, a circuit making andbreaking means in said latter circuit and connected to said operatorsfor operation thereby, said circuit making and breaking means includingmeans whereby energization of one of said operators will break theelectric circuit thereto, and simultaneously close the circuit to theother operator, a relay in said single circuit for breaking said circuitupon energization of one of said operators, and means for energizingsaid rst electro-magnetic operating member.

2. An attachment for a radio receiving apparatus having selective tuningmembers, an electro-magnetic operating member for each tuning member,circuit closing means for said operating member, a switch connected tothe supply source for the radio apparatus and connected to the radioapparatus, a switch operating circuit, an electro-magnetic operatorconnected to said switch for moving said switch to a circuit closingposition, a second electro-magnetic operator connected to said switchfor moving said switch to a circuit breaking position, a single electriccircuit for said electro-magnetic operators, a circuit making andbreaking means in said latter circuit and connected to said operatorsfor operation thereby, said circuit makingand breaking means includingmeans whereby energization of one of said operators will break theelectric circuit thereto, and simultaneously close the circuit to theother operator, said circuit making and breaking means also includingmeans whereby the breaking of the electric circuit to an operator isdelayed until an operator has substantially completed a cycle in itsoperation, a relay in said single circuit for breaking said circuit uponenergization of one of said operators, and means for energizing said rstelectromagnetic operating member.

3. An attachment for a radio receiving apparatus having selective tuningmembers, an electro-magnetic operating member for each tuning member,circuit closing means icr said operating member, a switch connected tothe supply source for the radio apparatus and connected to the radioapparatus, a switch operating circuit, an electro-magnetic operatorconnected to said switch for moving said switch to a circuit closingposition, a second electro-magnetic operator connected to said switchfor moving said switch to a circuit breaking position, a single electriccircuit for said electro-magnetic operators, a circuit making andbreaking means in said latter circuit and connected to said operatorsfor operation thereby, said circuit making and breaking means includingmeans whereby energization of one of said operators will break theelectric circuit thereto, and simultaneously close the circuit, to theother operator, said circuit making and breaking means also includingmeans whereby the breaking of the electric circuit to an operator isdelayed until an operator has substantially completed a cycle in itsoperation, a relay in said single circuit for breaking said circuit uponenergization of one of said operators, said relay including means forholding said single circuit closed for a period of time sucient topermit an operator to complete a cycle of its operation, and means forenergizing said rst electro-magnetic operating member.

4. An attachment for a radio receiving apparatus having selective tuningmembers, an electro-magnetic operating member for each tuning member,circuit closing means for said operating member, a switch connected tothe supply source for the radio apparatus and connected to the radioapparatus, a switch operating circuit, an electro-magnetic operatorconnected to said switch for moving` said switch to a circuit closingposition, a second electro-magnetic operator connected to said switchfor moving said switch to a circuit breaking position, a single electriccircuit for said electric-magnetic operators, a circuit making andbreaking means in said latter circuit and connected to said operatorsfor operation thereby, said circuit making and breaking means includingmeans whereby energization of one of said operators will break theelectric circuit thereto, and simultaneously close the circuit to theother operator, said circuit making and breaking means also including apair of loosely coupled members operable to delay the breaking of thecircuit to an operator until the operator has substantially completed acycle in its operation, a relay in said single circuit for breaking saidcircuit upon energization of one of said operators, and means forenergizing said rst electro-magnetic operating member.

5. An attachment. for a radio receiving apparatus having selectivetuning members, an electro-magnetic operating member for each tuningmember, circuit closing means for said operating member, a switchconnected to the supply source for the radio apparatus and connected tothe radio apparatus, a switch operating circuit, an electro-magneticoperator connected to said switch for moving said switch to a circuitclosing position, a second electro-magnetic operator connected to saidswitch for moving said switch to a circuit breaking position, a singleelectric circuit for said electric-magnetic operators, a circuit makingand breaking means in said latter circuit and connected to saidoperators for operation thereby, said circuit making and breaking saidcircuit upon energization of one of said operators, said relay includinga pair of loosely coupled members for holding said single circuit closedfor a period of time to permit an operator to complete a cycle of itsoperation, and means for energizing said rst electromagnetic operatingmember.

WILLIAM H. MURRAY.

